Glioblastoma multiforme (GBM) is an aggressive central nervous system (CNS) cancer characterized by enhanced tumor cell motility, pernicious invasion into the normal brain, extensive tumor-induced angiogenesis, and adaptive resistance to current therapeutic paradigms. One of the difficulties associated with GBM is the ability of the tumor cells to infiltrate normal CNS tissue. Neurosurgeons can remove the primary tumor mass, but peripheral cells that are inaccessible will ultimately result in a secondary lesion that can lead to death. The matrix metalloproteinases (MMP) are well known for their abilities to facilitate processes of cellular motility and invasion through their clearance of extracellular matrix (ECM). A specific member of this family, MMP-1, is not observed in normal brain, yet its expression is a common characteristic of GBM. The various causes of MMP-1 expression, and its consequences in GBM cells are unknown. As such, functional studies were conducted related to the induction of MMP-1 expression via another molecule intrinsic to GBM, nitric oxide (NO). The exposure of GBM cell lines to nanomolar concentrations of NO produced significant inductions of MMP-1 expression and GBM cell motility. The specific removal of MMP-1 with siRNA elicited an abrogation of NO-stimulated motility, suggesting a pathological contribution by this enzyme. Furthermore, recent accumulating evidence suggests that MMP-1 contributes to tumor cell survival and related angiogenesis in other cancer settings. To investigate these capabilities in GBM, cell lines were stably engineered to have either MMP-1 over-expression or knock-down. Both tumor formation and size were significantly reduced with MMP-1 knock-down and significantly increased with over-expression. In a model of GBM cell-induced angiogenesis, the presence of MMP-1 contributed to an angiogenic phenotype. Further angiogenesis studies revealed a significant recruitment of host endothelium to the tumor interstitium in vivo. Proteomic studies suggest that one mechanism by which MMP-1 could influence angiogenesis is through the easement of the anti-angiogenic tissue inhibitor of metalloproteinases-4 (TIMP-4), since the removal of MMP-1 elicits a significant increase in TIMP-4 detection. Altogether, these functional data present MMP-1 as a promising target for future therapeutic investigation, because it is unique to the GBM environment and contributes to key overlapping GBM pathologies.

Traumatic brain injury (TBI) is a serious health concern, causing cognitive, motor, and sensory deficits, including olfactory dysfunction. This dissertation explores the effects of TBI on synaptic plasticity within the olfactory system, seeking to define mechanisms guiding postinjury sensory reinnervation. Physical forces induced by TBI can axotomize olfactory receptor neurons (ORNs), which innervate olfactory bulb (OB). These axons regenerate OB projections after injury, a process involving growth through a complex extracellular matrix (ECM). As such, we investigated a potential molecular mechanism capable of modifying local OB ECM to support postinjury synaptogenesis. Since matrix metalloproteinases (MMPs) and their ECM substrates are recognized for TBI therapeutic potential, we explored the role of MMP9 and its substrate osteopontin (OPN) in promoting ORN reinnervation of the OB after mild fluid percussion injury (FPI). First, we confirmed that FPI deafferented the mouse OB. In Chapter 2, we showed concurrent activation of neuroglia, elevated spectrin proteolysis and reduction in ORN-specific olfactory marker protein (OMP). As OMP normalized during regeneration, growth associated protein-43kD (GAP-43) peaked, marking OB entry of ORN growth cones. Ultrastructural analysis revealed ongoing ORN axon shrinkage and degeneration, glial phagocytosis of cellular debris, and a reorganization of synaptic structure. To explore ECM role in mediating postinjury OB reinnervation, we defined the time course of MMP9 activity and several downstream targets. Chapter 3 reports biphasic MMP9 activity increase during acute/subacute degeneration, accompanied by robust generation of 48kD OPN cell signaling peptide. OPN receptor CD44 also increased during the acute/subacute interval, suggesting potential interaction of the two proteins. Finally, we utilized MMP9 knockout (MMP9KO) mice to confirm MMP9 role in OB synaptogenesis. In Chapter 4, MMP9KO reversed FPI-induced lysis of 49kD OPN and altered postinjury expression of ORN axon degeneration marker OMP. Additional ultrastructural analysis verified delayed recovery of OB synaptic features within the injured MMP9KO. Overall, we demonstrated that mild FPI elicits ORN axotomy to induce OB reactive synaptogenesis, and that MMP9 supports reinnervation by processing OPN for activation of local glia, cells which reorganize the ECM for synapse regeneration.

INTRODUÇÃO: Na patogênese da rotura do manguito rotador, diminuição da síntese e aumento da degradação das fibras colágenas são encontradas, associadas ao aumento da atividade das metaloproteinases da matriz 1 e 3 (MMP-1 e MMP-3). Há evidências que fatores genéticos estão envolvidos na produção das metaloproteinases e na etiologia da rotura do manguito rotador. O objetivo deste estudo foi avaliar a associação entre o polimorfismo genético das MMP-1 e MMP-3 com a rotura de espessura completa do manguito rotador. Como objetivos secundários, tivemos avaliar a correlação dos haplótipos da MMP-1 e MMP-3 com a rotura de espessura completa do manguito rotador e comparar se indíviduos com rotura transfixante do manguito rotador têm maior proporção de familiares com a mesma doença, em relação aos indíviduos controles. MÉTODOS: Avaliamos 64 pacientes com rotura transfixante do manguito rotador e 64 controles assintomáticos. Foram incluídos apenas pacientes com idade inferior a 65 anos e rotura de espessura completa não traumática. A rotura ou integridade do manguito rotador foi avaliada por ressonância magnética ou ultrassonografia em todos indivíduos. Os pacientes e os controles foram pareados por idade. O ácido desoxirribonucleico (DNA) dos voluntários foi obtido a partir de células epiteliais da mucosa bucal. Os genótipos das MMP-1 e MMP-3 foram determinados utilizando as técnicas de Reação em Cadeia de Polimerase (PCR) e Polimorfismo no Comprimento de Fragmentos de Restrição (RFLP). RESULTADOS: Observamos uma presença de 77% do alelo 1G e 64% do genótipo 1G/1G no grupo controle. Os pacientes com rotura transfixante do manguito rotador apresentaram uma taxa de 48% do alelo 2G e 73% de genótipos 1G/2G ou 2G/2G (p < 0,001). Indivíduos com genótipo 1G/2G e 2G/2G tiveram maior chance de ter uma rotura do manguito rotador: razão de chances (RC) igual a 4,8 (Intervalo de confiança de 95% [IC 95%] 2,1 a 11,0) e 5,2 (IC 95% 1,8 a 14,9), respectivamente. Também observamos uma distribuição significativamente diferente nos alelos e genótipos da MMP-3 (p = 0,045, p = 0,021, respectivamente) entre os casos e controles. Indivíduos com genótipo 5A/5A tiveram maior chance de apresentarem uma rotura do manguito rotador (RC 5,5; IC 95% 1,4 a 20,9). Indíviduos com haplótipo 2G/5A tiveram maior possibilidade de ter uma rotura do manguito rotador, este haplótipo foi encontrado em 42 de 64 pacientes (66%) e em 17 de 64 controles (27%), com razão de chances de 5,3 (IC 95% 2,5 a 11,3). Pacientes com rotura do manguito rotador relataram, em maior número (19 de 64 pacientes, 30%), a existência de familiares que realizaram tratamento para rotura do manguito rotador em relação aos pacientes controles (quatro de 64 pacientes, 6%; p = 0,001). CONCLUSÃO: O polimorfismo genético das MMP-1 e MMP-3 foi associado à rotura do manguito rotador / INTRODUCTION: In the pathogenesis of rotator cuff tear, decreased synthesis and increased degradation of collagen fibers are found, associated with an increase in activity of matrix metalloproteinases 1 and 3 (MMP-1 and MMP-3). There is evidence that genetic factors may be involved in metalloproteinase production and the etiology of rotator cuff tear. The aim of this study was to evaluate the association between the genetic polymorphism of MMP-1 and MMP-3 and full-thickness rotator cuff tear. As secondary aims, we measured the correlation of MMP-1 and MMP-3 haplotypes with full-thickness rotator cuff tears and compared if individuals with full-thickness rotator cuff tears have a higher proportion of relatives with the same disease than the control subjects. METHODS: We evaluated 64 patients with full-thickness rotator cuff tear and 64 asymptomatic controls. Patients aged below 65 years, with non-traumatic full thickness tears, were included. The rotator cuff tear or integrity was evaluated by magnetic resonance or ultrasound in all individuals. The patients and controls were paired by age. The deoxyribonucleic acid (DNA) of the volunteers was obtained from oral mucosa epithelial cells. MMP-1 and MMP-3 genotypes were determined using the Polimerase Chain Reaction (PCR) and Restriction Fragment Length Polymorphism (RFLP) assays. RESULTS: We observed a 77% presence of allele 1G and 64% of genotypes 1G/1G in the control group. The patients with full-thickness rotator cuff tear presented 48% of allele 2G and 73% of genotypes 1G/2G or 2G/2G (p < 0.001). Individuals with genotypes 1G/2G and 2G/2G were more likely to have a rotator cuff tear: odds ratio equal to 4.8 (95% confidence interval [95% CI] 2.1 to 11.0) and 5.2 (95% CI 1.8 to 14.9), respectively. We also observed a significantly different distribution in the alleles and genotypes of MMP-3 (p = 0.045, p = 0.021, respectively) among the cases and controls. Individuals with the 5A/5A genotype were more likely to have a rotator cuff tear (OR 5.5; 95% CI 1.4 to 20.9). Individuals with the haplotype 2G/5A were more likely to have rotator cuff tears develop, this haplotype was found in 42 of 64 patients (66%) and in 17 of 64 controls (27%) with odds ratio 5.3 (95% CI 2.5 to 11.3). Patients with rotator cuff tears reported, in higher number (19 of 64 patients, 30%), the existence of relatives who previously had treatment for rotator cuff tears compared to control patients (four of 64 patients, 6%; p = 0,001). CONCLUSION: The genetic polymorphism of MMP-1 and MMP-3 was associated with rotator cuff tear

Os tumores da cérvice-uterina, que representam uma das principais doenças ginecológicas em mulheres na idade reprodutiva em todo o mundo, estão etiologicamente associados com a infecção pelo papilomavírus humano (HPV). A progressão de uma lesão intraepitelial escamosa de baixo-grau (LSIL) a um carcinoma invasivo de cérvix uterina está acompanhada da degradação da matriz extracelular (MEC) devido à ação progressiva das metaloproteinases de matriz (MMP-2, MMP-9 e MMP-14) no processo de invasão e metástase. Entretanto, o balanço entre as MMPs e seus reguladores como RECK e TIMPs é necessário para controlar esta invasão. O objetivo deste projeto consiste em avaliar a atividade e a expressão das metaloproteinases 2, 9, e 14, e caracterizar a expressão do gene supressor de metástase RECK e do inibidor tecidual de metaloproteinases (TIMP-2), em modelo de queratinócitos humanos infectados com retrovírus recombinantes que expressam os oncogenes E6 e/ou E7 de HPV 16, em culturas cultivadas em monocamada e organotípicas. Para isso, utilizamos ensaios de real-time PCR, zimografia, western blot, imunocitoquímica, ensaio de ELISA e imunohistoquímica. Em culturas em monocamada observamos que as células que expressam as oncoproteínas E6E7 de HPV16 apresentaram menores níveis protéicos de RECK e TIMP-2 em relação ao controle pXLSN. Quando analisamos as culturas organotípicas, também observamos esta diminuição dos níveis de RNAm e protéicos de RECK em rafts que expressam E6E7, acompanhado pelo aumento da atividade de MMP-9, em relação ao controle. Também observamos que o tratamento das culturas com a citocina TNF aumenta a expressão gênica, protéica e atividade de MMP-9 em todas as linhagens analisadas. Além disso, os oncogenes E6 e/ou E7 não afetam a expressão e/ou atividade de MMP-2, MT1-MMP. Nossos dados demonstraram que a expressão das oncoproteínas E6E7 de HPV16 estão relacionadas com o desequilíbrio entre MMPS e seus inibidores, sugerindo que em uma fase pré-invasiva do carcinoma cervical, não somente as MMPs, mas, principalmente seus inibidores são críticos para início da progressão tumoral. / Cervical cancer is etiologically associated with to high-risk human papillomavirus (HPV) infection. It has been observed that matrix metalloproteinases (MMPs) -2, -9, and MT1-MMP are required for basement membrane degradation during cervical carcinoma progression. Moreover, a counterbalancing among MMPs and their regulators, such as TIMPs and RECK, is necessary to modulate invasion. In order to study the effect of HPV oncogenes on MMPs expression, primary human keratinocytes (PHKs) were infected with recombinant retroviruses expressing wild-type HPV16 E6 and/or E7 oncogenes and were used to seed monolayers and organotypic cultures. Quantitative real-time PCR (Q-PCR), western blot, zimography, immunocitochemistry, ELISA assay and immunohistochemistry were used to determine the expression level and activity of MMP-2, MMP-9, MT1-MMP and their inhibitors RECK and TIMP-2. We observed that cultures expressing E6E7 presented lower RECK and TIMP-2 protein levels than control keratinocytes. In addition, rafts cultures presented the same lower RECK levels additionally presenting higher MMP-9 activity than control. Furthermore, we observed that expression of E6 and/or E7 proteins do not affect MMP-2 and MT1-MMP protein levels and/or activity. We also observed that TNF treatment enhance the MMP-9 gene and protein expression and activity in all studied cell lines. Taken together, our results demonstrate that HPV16E6E7 expression is related with the unbalance between MMPs and their inhibitors, suggesting that in the initial steps of HPV-related cervical disease, not only MMPs but also RECK and TIMP-2 are critical for tumor progression.

Introdução: O Câncer de próstata (CaP) é o mais comum do homem brasileiro. É importante a identificação de alterações moleculares que possam prever o seu desenvolvimento e potencial biológico. Polimorfismos de nucleotídeo único (SNP) são alterações da seqüência do DNA onde somente uma base é trocada com uma freqüência superior a 1% na população, que podem levar a modificações estruturais e funcionais na proteína, ou afetar a sua quantidade, e podem constituir marcadores de predisposição e prognóstico de neoplasias. Metaloproteinases (MMP) são proteínas da família de enzimas proteolíticas, que degradam a matriz extracelular, e SNP na sua estrutura têm sido associados ao comportamento de tumores. Objetivos: Avaliar a freqüencia de SNP nos genes das MMP1, 2, 7 e 9, em pacientes com CaP e grupo controle, relacionando com suscetibilidade para o desenvolvimento da doença e previsão de seu potencial biológico. Material e Métodos: A amostra é constituída por tecido não tumoral de 100 indivíduos com CaP, e 100 amostras controle representadas por soro de indivíduos saudáveis, sem câncer de próstata. O DNA foi obtido utilizando protocolos convencionais de extração. Para genotipagem foi utilizada técnica de identificação de base única com uso de sondas marcadas com fluoróforos (Taqman®) pela técnica de reação em cadeia da polimerase em tempo real. As freqüências alélicas foram calculadas e a comparação entre os grupos foi feita utilizando-se o teste de qui-quadrado com valor de significância de 0,05. Resultados: Nos genes das MMP1 a freqüência do genótipo homozigoto polimórfico esteve mais presente no grupo controle que no CaP (p>0,001). No gene da MMP9 o alelo polimórfico esteve mais presente em pacientes com CaP (p>0,001), e em tumores com escore de Gleason6 (p=0,003). No gene da MMP2 de acordo com estadiamento patológico o alelo polimórfico foi mais freqüente em tumores pT3 (p=0,026) e Gleason maior ou igual a 7(p=0,042). Conclusão: Nossos resultados sugerem que o polimorfismo no gene da MMP1 está associado a um caráter de proteção aos indivíduos quanto ao desenvolvimento do CaP. O polimorfismo no gene da MMP9 está associado a um aumento no risco de desenvolvimento desta neoplasia, e quando analisamos as associações com os fatores prognósticos encontramos uma correlação com tumores de melhor prognóstico. Por outro lado o polimorfismo do gene da MMP2 se associa a tumores não órgãoconfinados / Introduction: Prostate cancer (PCa) is the most frequent tumor in males in Brazil. Research has been directed for the identification of molecular markers that can predict the PCa predisposition and prognosis. Single nucleotide polymorphisms (SNPs) are genome variations, present in a frequency of 1% or more. The matrix metalloproteinases (MMPs) are a family of enzymes responsible for the degradation of extracellular matrix. SNPs have been demonstrated in the promoter region of these genes and have been associated with development and progression of some cancers. Objective: To investigate the correlation between polymorphisms of MMP1, 2, 7, 9 with susceptibility and classical prognostic parameters in PCa. Patients and methods: The sample is constituted by normal tissue of 100 patients with PCa, and 100 healthy men as controls (serum). DNA genomic was extracted from paraffin blocks and serum using conventional protocols. The DNA sequence containing the polymorphic sites was amplified by Real-Time polymerase chain reaction, using fluorescent probes (Taqman®). The allelic frequency was calculated and the comparison between the groups was made using the qui-square test with value of significance of 0.05. Results: The polymorphic homozygote genotype of the MMP1 was more frequent in the control group than in the PCa (p<0.001). The polymorphic allele of MMP9 was more frequent in the PCa group (p<0.001), and in tumors Gleason6 (p=0,003). The polymorphic allele of MMP2 was more frequent in tumors of higher stage (pT3) (p=0.026) and higher Gleason Score (7) (p=0.042). Conclusion: We have shown that MMP1 polymorphism is more frequent in the control group, than in patients with PCa, it may be associated to protection for the development of PCa. The MMP9 polymorphism was related to higher risk for development of this neoplasia, but associated with lower Gleason score. MMP2 polymorphism was associated with non organconfined disease.

A paracoccidioidomicose é uma micose sistêmica caracterizada por ser uma doença granulomatosa. As formas benignas da doença são caracterizadas por uma infecção localizada, contendo granulomas compactos com poucos fungos; já nas formas mais graves, ocorre um processo granulomatoso frouxo com focos de necrose e intensa disseminação fúngica. Objetivou-se avaliar o desenvolvimento de lesões granulomatosas em baço, fígado, pulmão e epiplon de camundongos, após infecção pela via intraperitoneal com o isolado de alta virulência, Pb18, em diferentes períodos de infecção após tratamento com fármacos, os quais possuem mecanismo de ação relacionado com a alteração no balanço entre a síntese e degradação dos produtos do colágeno, interferindo diretamente na formação do granuloma A citocina IFN-<font face=\"Symbol\">g, o antibiótico Tetraciclina e as drogas antiinflamatórias Lumiracoxib e Celecoxib. Avaliamos a presença de alguns componentes do granuloma (colágeno, células do infiltrado inflamatório, de citocinas primordiais para sintese/degradação da MEC do granuloma, presença de P. brasiliensis). / Paracoccidioidomycosis (PCM) is a systemic mycosis that is endemic in Latin America, whose causative agent is the thermal dimorphic fungus Paracoccidioides brasiliensis (Pb). PCM is a granulomatous disease, and the formation of granulomas can be understood as a mechanism of the body to block and limit the invasiveness of the fungus or its antigenic components, once unable to lyse them. Bening forms of the disease are characterized by a localized infection, where granulomasa are compact and contain few fungi. More severe forms present loose granulomatous processes with foci of necrosis and severe fungal. Studies in which granulomatous response was developed in resistant (A/J) and susceptible (B10.A) mice to the high virulence isolate Pb18 showed the presence of different patterns of injuries related to the type of extracellular matrix (ECM) components and the different cells types in the area, suggesting a important role of these elements in the formation and constitution of the granuloma and thus the outcome of infection. In our project, we aimed to evaluate the development of granulomatous lesions in the spleen, liver, lung and omentum of mice susceptible to PCM after intraperitoneal infection with Pb18, at different periods of infection (acute and chronic) with or without treatment with drugs. These drugs have mechanisms of action closely related to the change in the balance between synthesis and degradation of collagen Thus, they interfere directly in the granuloma formation and in maintaining the viability of fungi and also with the development of fibrosis. Which is a common and devastating sequelae of numerous infections including the PCM, with the characteristic proliferation of fibroblasts and deposition of ECM. The treatments were chosen based on prior knowledge on their effects on the course of experimental murine PCM. IFN-<font face=\"Symbol\">g was chosen due to its antifibrotic effect, being an activator of macrophages in infection by P. brasiliensis and increasing the fungicidal effect of neutrophils. The antibiotic tetracycline was used because of its inhibitory effect on the synthesis of extracellular matrix, limiting antimicrobial activity and the ability of collagenase to degrade ECM. Finally, the antiinflammatory drugs Celecoxib and Lumiracoxib (inhibitors of the COX-2 enzyme) 11 were used because they cause an increase in the expression of collagen type III and type IV. We analyzed the components of the granuloma (collagen, inflammatory cells, cytokines essential for synthesis / degradation of the ECM of the granuloma, the presence of P. brasiliensis). Among the cytokines analyzed, we studied the importance of TNF-<font face=\"Symbol\">&#945 in the formation of granulomas and regulation of matrix metalloproteinases (MMP) synthesis and function. We analyzed TGF-<font face=\"Symbol\">b because it negatively modulate the secretion of nitric oxide by macrophages and promote the accumulation of ECM and is believed to be the central mediator of the process of fibrosis in several pathologies. IFN-<font face=\"Symbol\">g was studied because of its correlation to the preferential Th1 immune response in diseases and infectious processes of fungal and bacterial infections, and also because it modulates fibroblast function.

A ação das metaloproteinases de matriz (MMP-2, MMP-9 e MT1-MMP) é necessária para degradação da membrana basal em carcinomas da cérvice uterina. O objetivo deste trabalho consistiu na avaliação da expressão das metaloproteinases MMP -2, -9 e MT1-MMP, do gene supressor de metástase RECK e do inibidor tecidual de MMPs (TIMP-2) em modelo de células de neoplasia da cérvice-uterina cultivadas em substratos de matriz extracelular. As linhagens celulares de carcinoma de cérvice uterina SiHa, CaSki, ambas HPV 16 positivas, e C33A, HPV negativa, foram cultivadas em gel de colágeno tipo I, Matrigel e plástico. Avaliou-se o crescimento, invasão, expressão gênica, através de ensaios de real-time PCR, e atividade de metaloproteinases, através de ensaios de zimografia. Os resultados demonstraram que estas linhagens de carcinoma cervical quando cultivadas em gel de colágeno tipo I apresentaram uma diminuição no crescimento, morfologia modificada na presença de substrato de matriz extracelular, e que nas linhagens HPV positivas há um aumento da expressão de MMP-2, MT1-MMP e TIMP-2 e da atividade de pró-MMP-2 em relação à linhagem HPV negativa. Observou-se também que, RECK apresentou maior expressão gênica em CaSki associada à atividade de pró-MMP-2. MMP-9 apresentou muito baixa expressão gênica em todas as linhagens e condições estudadas. Quando analisamos as linhagens separadamente, observamos que o Matrigel influenciou a expressão gênica de MMP-2, e que o gel de colágeno tipo I aparece como indutor da atividade de pró-MMP-2 em todas as linhagens. Em conclusão, nossos resultados mostram que a expressão de MMP-2, MT1-MMP e TIMP-2 e que a atividade de pró-MMP-2 estão aumentadas nas células HPV positivas, sugerindo que o HPV está associado com a expressão de MMPs e TIMP-2. / Matrix metalloproteinases (MMPs) -2, -9, and MT1-MMP are required for basement membrane degradation in cervical carcinoma. We evaluated the expression and activity of MMPs and their inhibitors RECK and TIMP-2 in three human invasive cervical carcinoma cell lines. Two HPV-16- positive cell lines (SiHa and CaSki), HPV-negative cell line (C33A) were cultured either onto type-I collagen gel, Matrigel or plastic, in order to recreate their three-dimensional growth environment and evaluate the growth and invasion of the cells and expression of these genes using quantitative real-time PCR (Q-PCR). We also analyzed the gelatinolytic activity of MMP-2 and -9 by zymography. We found that the growth curves carcinoma cells are decreased and cells morphology are modified in ECM substrate. HPV-positive cell lines expressed higher levels of MMP-2, MT1-MMP and TIMP-2 than the HPV negative cell line. In addition, MMP-9 was expressed at very low levels in both HPV-negative and HPV-positive cell lines. We also observed that the expression of the RECK gene is higher in CaSki cells, being associated with pro-MMP-2 activity. The Matrigel substrate influence MMP-2 expression for SiHa and CaSki cells. On the other hand, we found that type-I collagen gel, but not Matrigel, can enhance pro-MMP-2 activity in all cell lines. Our results suggest that the presence of HPV is related to increased expression of MMP -2, MT1-MMP and TIMP-2 and pro-MMP-2 activity in HPV-positive cells than in HPV-negative cells.

Methotrexate (MTX) is an antimetabolite anticancer agent that is used in treatment of multiple cancers, such as acute lymphoblastic leukaemia and osteosarcoma. A lack of selective tumour toxicity is one of the major problems associated with MTX chemotherapy, especially when given at high doses, as in high dose MTX (HDMTX) therapy. MTX causes various toxicity problems including life-threatening nephrotoxicity, haematological toxicity and neurotoxicity. Overcoming this toxicity is of great importance and has been attempted in various ways, not least via the design of prodrugs. The concept of tumour protease, and specifically matrix metalloproteinase (MMP), activated prodrugs was the focus of the work described in this thesis. This concept relies upon attachment of an MMP-sensitive peptide sequence to a specific site in a drug structure, so as to inactive it. The activity of the parent drug is restored once it is activated by the MMPs in the tumour microenvironment. In this work, different MMP-sensitive peptide sequences linked to MTX were synthesised, resulting in 63 MTX prodrugs. The MMP-mediated activation of these conjugates in tumour tissues (specifically HT1080 homogenates) ex vivo was assessed and the results were compared to the activation of these conjugates in various normal tissues specifically liver, kidney and lung. Specific criteria were established for the selection of promising conjugates for more detailed study. From 7 promising compounds, compound 75 was identified as the lead prodrug, demonstrating selective MMP activation, as indicated by inhibition of its activation by broad spectrum MMP inhibitor ilomastat. The pharmacokinetics of compound 75 was studied in tumour (HT1080) xenograft-bearing mice and the results were compared to those obtained from administration of equimolar doses of conventional MTX. Compound 75 led to enhanced tumour concentrations of MTX, with reduced exposure to normal tissues in vivo compared to conventional MTX therapy. Furthermore, the efficacy of equimolar doses of compound 75 and directly dosed MTX in reduction of HT1080 volume were compared. Superior antitumour activity was observed with compound 75 compared to MTX treatment. Compound 75 is the first example of an MMP-activated prodrug to be reported with enhanced therapeutic index, as evidenced by a full in vivo pharmacokinetic analysis and normal tissue metabolism data. The data presented in thesis support the concept of MMP-activated prodrug development, and form a strong foundation upon which to develop a clinicallyuseful MTX prodrug, with the potential to enhance efficacy and reduce toxicity to the patient.

冠狀動脈旁路移植術是治療合併左主幹及多隻冠狀動脈狹窄性病變患者的理想方法。然而靜脈橋失效極大地限制了冠脈搭橋手術的遠期療效。基於對靜脈橋失效潛在機制的研究，近年來開發出了多種針對性的防治手段。但是除了積極的降脂治療，目前尚未有其它療法獲得臨床證實可以有效改善靜脈橋遠期通暢率。所以，本研究旨在探索與防治靜脈橋再狹窄相關的新型生物標靶和防治策略。 / 我們應用豬大隱靜脈植入頸內動脈模型，觀察骨橋蛋白是否參與靜脈橋動脈化進程以及其與基質金屬蛋白酶功能活動的關係。我們發現骨橋蛋白表達在靜脈橋動脈化過程中顯著增加，並且與基質金屬蛋白酶2/9和增殖細胞數量的變化同步。此外，骨橋蛋白富集區域在靜脈橋內的再分佈與血管壁重構進程相關。這些結果表明, 骨橋蛋白積極參與了靜脈橋壁重構，而抑制骨橋蛋白表達作為防治靜脈橋失效的治療策略值得深入研究。 / 我們運用體外培養的方法研究了在高糖環境中骨成形蛋白4與靜脈內皮細胞舒張功能障礙的關係。我們發現，骨成形蛋白4在糖尿病患者的大隱靜脈與高糖培養的人臍靜脈內皮細胞中顯著增加；而骨成形蛋白4的高表達與靜脈血管內皮細胞依賴性舒張功能受損有關。本研究結果為解釋糖尿病患者有著較高的冠脈搭橋術後靜脈橋失效率提供了新證據，同時也為改善此類患者靜脈橋通暢率提出了潛在的治療靶點。 / 通過轉染金屬蛋白酶-3抑制物 (TIMP-3)基因來針對性地抑制血管中層平滑肌細胞的遷移和增殖，可以有效地減少靜脈橋新生內膜增生。基於前期研究，我們觀察了在豬模型中運用重組腺病毒轉載TIMP-3(RAdTIMP-3) 防治靜脈橋狹窄的遠期效果(3個月)。結果發現，即使在腺病毒載體已被清除的情況下，RAdTIMP-3對靜脈橋的良性保護作用仍持續存在。此外，我們通過比較術後7天與3個月獲取的橋血管中炎性標記物表達的差異，發現腺病毒轉染並未對靜脈橋造成長期的炎性損害。因此，我們認為RAd-TIMP3基因能夠安全有效地防治靜脈橋遠期狹窄。本研究結果為TIMP-3基因治療轉化至臨床實踐提供了可靠的前期證據。 / Coronary artery bypass grafting (CABG) remains the “gold standard“ for treating high-risk patients with unprotected left-main or multi-vessel coronary lesions. However, the long-term success of CABG is largely limited by an inadequate patency of saphenous vein grafts. To date, various therapeutic strategies targeting at the underlying mechanisms involved in the pathogenesis of vein graft failure (VGF) have been proposed and tested. However, apart from lipid-lowering therapy, no other intervention appears to have sustained benefits on improving vein graft patency in the clinical setting. Therefore, the aim of this study is to explore novel sets of molecular targets and effective therapeutic strategies to prevent VGF. / Novel molecules involved in the pathogenesis of vein graft failure / Using a porcine model, we assessed the involvement of osteopontin (OPN) in the venous arterialization and its relationship with the matrix metalloproteinases (MMPs). We found that the expression of OPN was significantly increased over the 3-month study period. Moreover, the expression of OPN at different time points well correlated with the fluctuating activities of MMP-2/9 and the number of proliferative cells. We also observed a time-dependent redistribution of OPN protein accumulating in different layers of the venous wall. These findings suggest a contributory role of OPN protein involved in the process of vein graft wall remodeling. / We used pig and human saphenous veins (SVs), as well as human umbilical endothelial cells (HUVECs), to investigate the changes of bone morphogenic protein-4 (BMP4) expression and its effects on endothelium-dependent relaxations (EDRs) under hyperglycemic conditions. Our results demonstrated a marked increase of BMP4 expression in SVs from diabetic patients and in HUVECs cultured with hyperglycemic medium. Moreover, such an increase of BMP4 contributes significantly to the impaired EDRs in venous conduits. Our findings add novel evidence that helps explain the high prevalence of VGF in diabetic patients undergoing CABG, and also suggest BMP4 as a potential therapeutic target to improve vein graft patency in this population. / Novel Therapeutic Strategy -- Gene Therapy / Aiming at blocking the development of neointima formation caused by vascular smooth muscle cells migration and proliferation, genetic transfection of tissue inhibitor of metalloproteinases-3 (TIMP-3) to vein grafts has shown promising results. Based on our previous study, we used recombinant adenoviruses that carry TIMP-3 (RAdTIMP-3) as a therapeutic gene to evaluate its long-term (3 months) effects on the pathological vein graft wall thickening in vivo. We found that the RAdTIMP-3-treated vein grafts had significantly reduced intimal and medial thickness compared with grafts from the control groups at 3 months, even after adenoviruses had already been cleared from transduced tissue. Furthermore, by assessing the amount of macrophages and the level of three inflammatory biomarkers within grafts harvested at 7 days and 3 months after implantation, we did not observe any detrimental effects of adenoviral transfection on the inflammatory status within the vein grafts. We therefore concluded that overexpression of TIMP-3 could effectively inhibit vein graft wall over-thickening in the longer-term. Our findings suggested the ex vivo RAdTIMP-3 gene therapy an attractive candidate for future clinical translation. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Hu, Jia. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 109-143). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.i / Declaration --- p.vii / Acknowledgement --- p.viii / Table of Contents --- p.x / List of Abbreviations --- p.xvi / List of Figures/Tables --- p.xviii / Chapter Chapter I --- INTRODUCTION --- p.1 / Chapter 1.1 --- SAPHENOUS VEIN GRAFTS IN CORONARY REVASCULARIZATION --- p.3 / Chapter 1.1.1 --- The use of venous conduits in CABG --- p.3 / Chapter 1.1.2 --- The long-term patency of saphenous vein grafts --- p.4 / Chapter 1.1.3 --- PCI for vein graft diseases --- p.6 / Chapter 1.1.4 --- Vein graft failure and adverse clinical outcomes --- p.7 / Chapter 1.2 --- MORPHOLOGY AND PHYSIOLOGY OF A NORMAL SAPHENOUS VEIN --- p.8 / Chapter 1.3 --- THE PATHOPHYSIOLOGY OF VEIN GRAFT FAILURE --- p.10 / Chapter 1.3.1 --- The quality of vein grafts prior to grafting --- p.10 / Chapter 1.3.1.1 --- Pre-existing endothelial dysfunction --- p.10 / Chapter 1.3.1.2 --- Surgical injuries --- p.11 / Chapter 1.3.2 --- Mechanisms of the pathological vein graft wall thickening --- p.12 / Chapter 1.3.2.1 --- Platelet activation and coagulant cascade --- p.13 / Chapter 1.3.2.2 --- Leukocytes recruitment and inflammation --- p.13 / Chapter 1.3.2.3 --- Hemodynamic forces --- p.14 / Chapter 1.3.2.4 --- Growth factors and VSMCs activation --- p.15 / Chapter 1.3.2.5 --- Contribution of adventitial and graft-extrinsic cells --- p.16 / Chapter 1.3.2.6 --- Oxidative stress --- p.17 / Chapter 1.3.2.7 --- Concomitant risk factors and vein graft atherosclerosis --- p.17 / Chapter 1.4 --- STRATEGIES FOR THE PREVENTION OF VEIN GRAFT FAILUR --- p.18 / Chapter 1.4.1 --- Minimizing surgical injuries --- p.18 / Chapter 1.4.2 --- Pharmacologic interventions --- p.19 / Chapter 1.4.3 --- External supports --- p.21 / Chapter 1.4.4 --- Genetic engineering of the vein graft --- p.23 / Chapter 1.4.4.1 --- Delivery systems --- p.23 / Chapter 1.4.4.2 --- Therapeutic strategies of the genetic modulation --- p.25 / Chapter 1.4.4.2.1 --- Antithrombotic and anticoagulant strategies --- p.25 / Chapter 1.4.4.2.2 --- Therapies for endothelial protection and regeneration --- p.27 / Chapter 1.4.4.2.3 --- Reducing inflammation and atherosclerosis --- p.28 / Chapter 1.4.4.2.4 --- Antioxidative therapy --- p.29 / Chapter 1.4.4.2.5 --- Therapies targeting at the cellular proliferation --- p.29 / Chapter 1.4.4.2.6 --- Inhibiting extracellular matrix reorganization --- p.31 / Chapter 1.5 --- CONCLUSIONS --- p.32 / Chapter Chapter II --- MATERIALS AND METHODS --- p.34 / Chapter 2.1 --- MATERIALS --- p.35 / Chapter 2.1.1 --- Reagents and equipment --- p.35 / Chapter 2.1.1.1 --- General materials and equipment for animal model --- p.35 / Chapter 2.1.1.2 --- General reagents and equipment for western blot --- p.35 / Chapter 2.1.1.3 --- General reagents and equipment for immunohistochemistry --- p.36 / Chapter 2.1.1.4 --- General reagents and equipment for venous ECs functional studies --- p.37 / Chapter 2.1.2 --- Buffers --- p.37 / Chapter 2.1.2.1 --- Buffers for human and animal samples --- p.37 / Chapter 2.1.2.2 --- Buffers for western blot --- p.38 / Chapter 2.1.2.3 --- Immunohistochemistry buffers --- p.39 / Chapter 2.1.2 --- Antibodies and adenoviral vectors --- p.41 / Chapter 2.2 --- METHODS --- p.41 / Chapter 2.2.1 --- Animal model --- p.41 / Chapter 2.2.2 --- Functional studies --- p.44 / Chapter 2.2.3 --- Human endothelial cells culture --- p.44 / Chapter 2.2.4 --- Western blot analysis --- p.45 / Chapter 2.2.5 --- Immunochemistry and immunofluorescence --- p.46 / Chapter Chapter III --- ROLE OF BMP4 IN VENOUS ENDOTHELIAL DYSFUNCTION --- p.47 / Chapter 3.1 --- INTRODUCTION --- p.48 / Chapter 3.2 --- MATERIALS AND METHODS --- p.49 / Chapter 3.2.1 --- Patient characteristics --- p.49 / Chapter 3.2.2 --- Preparation of human vein segments --- p.51 / Chapter 3.2.3 --- Porcine saphenous veins culture --- p.51 / Chapter 3.2.4 --- Functional studies of vein segments --- p.52 / Chapter 3.2.5 --- Cell culture --- p.53 / Chapter 3.3.6 --- Western blot analysis of BMP4 --- p.53 / Chapter 3.3.7 --- ROS measurement by dihydroethidium fluorescence imaging --- p.54 / Chapter 3.2.8 --- Statistical analysis --- p.54 / Chapter 3.3 --- RESULTS --- p.54 / Chapter 3.3.1 --- ACh-induced EDRs are impaired in diabetic veins --- p.54 / Chapter 3.3.2 --- The expression of BMP4 is upregulated under hyperglycemic condition --- p.55 / Chapter 3.3.3 --- BMP4 induces venous endothelial dysfunction in diabetes --- p.56 / Chapter 3.3.4 --- BMP4 impairs EDRs in cultured porcine saphenous veins --- p.58 / Chapter 3.4 --- DISCUSSION --- p.59 / Chapter 3.5 --- CONCLUSIONS --- p.62 / Chapter Chapter IV --- ROLE OF OSTEOPONTIN IN VEIN GRAFT REMODELING --- p.63 / Chapter 4.1 --- INTRODUCTION --- p.64 / Chapter 4.2 --- MATERIALS AND METHODS --- p.66 / Chapter 4.2.1 --- Surgical procedures --- p.66 / Chapter 4.2.2 --- Immunohistochemistry --- p.67 / Chapter 4.2.3 --- Western blot --- p.68 / Chapter 4.2.4 --- Gelatin zymography --- p.69 / Chapter 4.2.5 --- Cell proliferation --- p.69 / Chapter 4.2.6 --- Statistical analysis --- p.69 / Chapter 4.3 --- RESULTS --- p.70 / Chapter 4.3.1 --- Expression and redistribution of OPN protein within the venous wall --- p.70 / Chapter 4.3.2 --- The fluctuating expression of the matrix metalloproteinases --- p.72 / Chapter 4.3.3 --- Vascular smooth muscle cells proliferation --- p.74 / Chapter 4.4 --- DISCUSSION --- p.75 / Chapter 4.5 --- CONCLUIONS --- p.79 / Chapter Chapter V --- TIMP-3 GENE THERAPY FOR NEOINTIMA FORMATION --- p.81 / Chapter 5.1 --- INTRODUCTION --- p.82 / Chapter 5.2 --- MATERIALS AND METHODS --- p.84 / Chapter 5.2.1 --- Materials --- p.84 / Chapter 5.2.2 --- Grafting of pig saphenous veins and adenoviral transfection --- p.84 / Chapter 5.2.3 --- Histologic and morphometric analysis of the vein graft --- p.87 / Chapter 5.2.4 --- Immunocytochemistry --- p.87 / Chapter 5.2.5 --- Data analysis and statistics --- p.88 / Chapter 5.3 --- RESULTS --- p.89 / Chapter 5.3.1 --- Histologic and morphometric analysis of the vein graft --- p.89 / Chapter 5.3.2 --- Overexpression of TIMP-3 in porcine interposition grafts --- p.91 / Chapter 5.3.3 --- Endothelial cell coverage and VSMCs content --- p.92 / Chapter 5.3.4 --- Inflammation in vein grafts --- p.92 / Chapter 5.4 --- DISCUSSION --- p.97 / Chapter Chapter VI --- SUMMARY AND DISCUSSION OF MAJOR FINDINGS --- p.103 / Chapter 6.1 --- SUMMARY AND DISCUSSION --- p.104 / Chapter 6.1.1 --- The role of BMP4 in the pathogenesis of venous endothelial dysfunction --- p.104 / Chapter 6.1.2 --- The involvement of osteopontin in the process of vein graft remodeling --- p.105 / Chapter 6.1.3 --- Sustained benefits of adenoviruses-mediated TIMP-3 gene transfer in reducing vein graft neointima formation --- p.106 / Chapter 6.1.4 --- The inflammatory responses induced by adenoviral transfection --- p.106 / Chapter 6.1.5 --- Perspectives: novel therapeutic targets and clinical translation --- p.107 / Chapter 6.2 --- CONCLUSIONS --- p.108 / REFERENCES --- p.109 / PUBLICATION LIST --- p.144

Improvements in medical care over recent decades have increased the number of premature and low birth weight infants that survive hypoxic-ischemic (H-I) insults. Because there is a rising incidence in diseases associated with these events, it is critical to develop effective therapies to treat the various resulting neuropathies. Extracellular matrix constitutes the majority of brain parenchyma. Lecticans and matrix-degrading proteases including ADAMTSs (a disintegrin and metalloproteinase with thrombospondin repeats) and matrix metalloproteinases (MMPs) exert effects on cell viability and may be associated with either protective or destructive processes after H-I. Both ADAMTSs (Cross et al. 2006; Tian et al. 2007) and MMPs (del Zoppo et al. 2007; Gu et al. 2005; Rosenberg et al. 2001) have been associated with pathological states in brain, yet the relative contributions of lecticans, ADAMTSs and MMPs to inflammation and cell death remain unknown. In the present study, the first series of experiments were conducted to characterize cellular damage and neuroinflammation in the postnatal day 7 rat after exposure to H-I, and to determine if cell death and inflammation were associated with alterations in lectican expression. Data showed that reduced brevican expression occurred 4 days after H-I in lesioned hippocampus. Additionally, reduced versican expression in white matter was concomitant with pre-OL cell death at this endpoint. In contrast, both lecticans were elevated at later endpoints (14, 21 days) that were associated with increased neuroinflammation and cavitary infarction. These data suggest that lectican loss is associated with cell death at the early endpoint, whereas increased lectican deposition over time likely leads to glial scar formation and a reduced capacity for neuroplasticity. Two subsequent series of experiments were conducted to determine the relative contributions of matrix-degrading proteases to injury, and whether proteolytic activity was associated with neuroinflammatory events. The first objective was to determine whether treatment with AG3340, a selective inhibitor of gelatin-degrading MMPs, or the anti-inflammatory compound minocycline, could provide neuroprotection when administered at a delayed time point after insult, and to compare the efficacy of AG3340 with that of the well-known anti-inflammatory compound minocycline. Data showed that both compounds effectively dampened the recruitment of microglia/macrophages to the lesion site when administered 24 hrs after H-I. These effects were associated with reduced neurodegeneration, indicating that these compounds neuroprotect at a clinically relevant time point. The final series of experiments tested whether these compounds could neuroprotect in an ex vivo model of oxygen glucose deprivation (OGD) that lacks peripheral immune cell involvement, thus providing insight into the relative contributions of resident microglia and gelatinase activity to the inflammatory sequelae. Results showed that both compounds blocked the OGD-induced increase in gelatinase activity and were neuroprotective in the absence of peripheral immune cells. Taken together, these data indicate that resident microglia contribute to H-I injury through gelatinase activation. Thus, the present study demonstrates that gelatin-degrading MMPs are important targets to consider when developing therapies to combat neonatal H-I injury.